Perhaps trusty Prince is working with Queen (8)
I believe the answer is:
prisoner
'perhaps trusty' is the definition.
(I know that trusty is a type of con)
'prince is working with queen' is the wordplay.
'prince' becomes 'pr'.
'working' becomes 'on' (on can mean working or activated).
'with' is a charade indicator (letters next to each other).
'queen' becomes 'ER' (abbreviation for Elizabeth Regina).
'pr'+'is'+'on'+'er'='PRISONER'
(Other definitions for prisoner that I've seen before include "Incarcerated person" , "Inmate doing porridge" , "Condemned" , "One kept confined" , "Rep irons out the captive" .)